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VATIS Update Non-conventional Energy . Jul-Aug 2005

VATIS Update New and Renewable Energy (formerly Non Conventional Energy)* is published 4 times a year to keep the readers up to date of most of the relevant and latest technological developments and events in the field of New and Renewable Energy. The Update is tailored to policy-makers, industries and technology transfer intermediaries.

———————* This update has been renamed as 'VATIS Update: New and Renewable Energy' from Jan-Mar 2015 onwards.

IN THE NEWS

Fuel cell components to make a US$100 billion market

Latest projections from Research and Markets (R&M) reveal that the global market for fuel cell parts will be worth about US$100 billion in 2013. Analysts expect the demand for fuel cell components to increase dramatically, in light of developments in hand-held digital device and automotive markets. It is anticipated that the hand-held devices market would grow more rapidly as PDAs, mobile phones and similar devices tend to have a shorter shelf-life. On the other hand, motor vehicles need reliable power supplies, which is expected to make the development of this segment a little slower. According to analysts, The driving force behind fuel cell growth is the reality that fossil fuels are running out and is ultimately too expensive as an energy source. While power can be generated from solar and wind resources, there is a greater need for energy storage.

Hydrogen is an effective means of storage for electrical power. Developing a suitable way to manufacture and store hydrogen is seen as a key factor in developing fuel cell-powered cars for private ownership.

Fund for Asian clean energy

The Renewable Energy and Energy Efficiency Partnership (REEEP), a coalition of businesses and governments, will help create a 50 million (US$61.05 million) corpus for financing renewable energy investments in Asia. The Fund, to be set up in Bangkok, will provide services and capital for 10-15 renewable projects in China and India. According to Mr. Herkko Lehdonvirta, the manager of the Fund, Awareness and willingness to invest in sustainable energy has increased dramatically... mainly due to the ratification of the Kyoto Protocol and the start of the European Union emissions trading scheme. REEEP states that emissions of about 20-30 million tonnes of carbon dioxide (CO2), a greenhouse gas, could be eliminated. In Europe, CO2 prices hit a record high of over 29 per tonne in July, as the power utilities tried to comply with emissions caps.

The projects could have a total cost of up to 400 million and an estimated capacity of 150-500 MW of power. Establishing innovative funding and finance mechanisms are essential to mobilize the massive amounts of capital needed, stated Ms. Marianne Osterkorn, REEEP Director. The International Energy Agency observed that 16 trillion of investment is required over the next 25 years to calm record oil prices and ensure energy supplies would meet the rising global demand being led by fast-growing China.

Green energy project to provide energy for 350,000 Indians

An integrated renewable energy project estimated to cost about US$34 million will be established to provide electricity to over 350,000 people in the Sunderbans region in India. This was announced by Mr. S.P. Gon Choudhuri, Director of the West Bengal Renewable Energy Development Agency (WBREDA), during a symposium organized by the Indo-German Chamber of Commerce on renewable energy. For this project, the central government will provide 50 per cent of the amount while the balance will be put up jointly by the state government and grants from Germany. WBREDA had recently installed the first wind-diesel hybrid power plant in India at Sagar Island and also the nations largest off-grid biomass gasifier power plant to electrify five villages in the Sunderbans region. By 2010, at least 10 per cent of West Bengals power would come from renewable energy. Two million inhabitants would be supplied with electricity from renewable energy projects. Mr. Choudhuri said renewable energy aided distributed power generation and off-grid supply in remote rural areas where access to grid was costly and time consuming.

Large ocean energy project in China

The Chinese government has inked a pact with Tidal Electric, the United Kingdom, for setting up a tidal power project. The 300 MW renewable energy project, to be located near the mouth of Yalu River, would be the largest such project in the world, way ahead of the 240 MW French tidal power plant in LaRance.

Tidal Electrics offshore tidal power generation, also known as tidal lagoons, is a new approach to tidal energy conversion which resolves environmental and economic hurdles faced with the conventional tidal barrage technology. Tidal lagoons use a rubble mound impoundment structure and low-head hydroelectric generating equipment stationed at about 1.6 km or more offshore in a high tidal range area. Shallow tidal flats are the most economical sites. Multi-cell impoundment structures provide higher load factors (about 62 per cent) and have the flexibility to shape the output curve in order to dispatch power as prescribed by demand price signals.

IREDA News, October-December 2004

Indian PV unit picks American equipment

Spire Corp., the United States, is to provide EMMVEE Solar Systems Pvt. Ltd., India, with an advanced photovoltaic (PV) module production line. SPI-LINE 5000M includes automated equipment for solar cell stringing and lay-up, lamination, module testing and related training. EMMVEE Solar Systems selected Spire Corp. as its production line supplier based on Spires proven experience, equipment quality and training programme. Shipment of the production line is expected to begin in the fourth quarter of 2005.

EMMVEE Solar Systems Pvt. Ltd. was founded in 1992 with the goal of providing solar power to households at a low cost, contributing to a cleaner, greener and safer environment. The company produces and installs solar thermal and solar PV products. EMMVEE Solar Systems has already set up more than 40,000 solar water heaters under the brand name Solarizer in homes and institutions across India.

India moves on with development of fuel cell vehicles

The Indian Minister of State for Non-Conventional Energy Sources, Mr. Vilas Muttemwar, stated that work on the development of hydrogen fuel cells to power motor vehicles was progressing as per schedule. The Hydrogen Energy Board was striving hard to ensure that India remains on par with the rest of the world in this sector. Reacting to the United States claims that five per cent of its cars on road would be run by hydrogen power in the next 20 years, Mr. Muttemwar said that India can achieve enough progress to make similar claims. As fossil fuels are likely to get exhausted within 90 years, steps have to be taken to ensure alternative fuels.

China to focus on clean-fuel vehicles

The State Development and Reform Commission (SDRC), China, would focus on developing clean-fuel automobiles in order to save 38 million tonnes of petroleum. This was stated in a recent directive of SDRC on a medium- to long-range programme for energy saving. Notably, SDRC will strive to:

Chinas largest wind power project

Chinas Gansu province will house the countrys largest wind power project. Work on the 1,000,000 kW wind power plant is under way. This project will play an important role in the development of new and clean energy resources, providing respite to the power-starved eastern and western areas.

Indian wind energy sector records high growth rate

Wind energy is fast emerging as an economically viable option to meet the current energy deficit in India. With an installed capacity of over 3,000 MW, as of December 2004, wind energy production has amplified by 36 per cent. As such, wind energy accounts for about 3 per cent of the overall installed capacity in the power sector. With Indias land-based potential being 65,000 MW (source: the Indian Wind Energy Association InWEA), the existing wind power projects have already fed about 14 billion units of electricity to various state grids.

At present, Indias indigenous wind energy equipment manufacturing capacity is in excess of 1,000 MW per annum. Wind technology has evolved over the years and the predominant machine size in the market has increased from 55 kW in 1985 to 1 MW in 2004. Increasing awareness of the wind energy sectors potential has led to the identification of more than 200 sites, with wind speeds having been measured at nearly 600 locations in the country. Dr. Ajay Mathur, Governing Council member of InWEA, says that wind energy has emerged as one of the fastest growing alternative energy options. Currently, India is the fifth largest producer of wind energy in the world.

Wind energy sector has the potential for emerging as a technologically advanced and economically viable source of electricity on a large scale and as such contribute significantly to the national grid. To this end, the sector requires continued support from the goverment in the short term. Dr. Mathur observes that The process is already on with various in-centives, accelerated depreciation, preferential tariff, and wheeling and banking agreements. Progress in the power sector reforms as well as implementation of the Electricity Act 2003 are all notable steps in this direction. Dr. Mathur, however, feels that additional streamlining and a review of the existing support from the government are required.

Large silicon wafer manufacturing facility opens in China

Xinjiang Sunoasis Co. Ltd., China, participated in an opening ceremony for a new industrial park in Xinjiang Autonomous Region. The industrial park will be the site of a three-year project to develop a 100 MW silicon wafer production facility. The new production facility will incorporate technically advanced equipment, obtained locally as well as from overseas. It would have a total annual production capacity of 70 MW for monocrystalline and 30 MW of polycrystalline silicon wafers in 2007. Initially, the production target is set for 46 MW of monocrystalline silicon wafers, scheduled to commence production at the end of 2005. The facility will focus on large diameter thin wafers, which are said to be in great demand and will be needed to support what the company portrays as the booming solar market in China.

China targets wind energy development

By 2010, China plans to develop an advanced wind power system with a generating capacity of 4,000,000 kW reports Mr. Xu Dingming, the Director of the State Development and Reform Committees (SDRC) energy bureau. China has set up 43 wind power plants nationwide, with 1,300 installed wind power sets. However, the nations installed wind power generating capacity is a mere 760,000 kW. The country has rich wind resources and a huge potential for wind power development. SDRC will prioritize wind power development and plans to raise the installed wind power generating capacity to 20 million kW by 2020.

Fuel cell car in Malaysia

Malaysia recently saw the launch of its first fuel cell-based street ready car. Introduced by Agni a company involved in fuel cell development, fuel processing and energy storage the Renewable Energy Automobile (REAL) is a first-generation fuel cell car that runs on hydrogen. The unit incorporates an integrated energy generation and storage system, an electric propulsion unit and a control and instrumentation system. Agni has developed a custom platform for optimum positioning of various components, while making each one as compact and lightweight as possible. During the first phase of optimization tests, REAL would be tested on various terrains as well as temperature and weather zones.

China to build offshore wind farms

Offshore wind farms will play a major role in Chinas renewable energy programme spanning over the next 2-3 decades. The wind turbine sites, which would be built 50 km out to sea, would be ideally situated to supply clean power to the populous and booming east coast area. Mr. Shi Pengfei, Vice-chairman of the Chinese Wind Energy Association, observed that offshore wind sites are close to main electricity load centres in eastern China, and as such they offered great potential for future energy supply.

Sea winds could be harnessed to generate an estimated 750 GW, though few projects are under way. This will be about 70 per cent higher than the countrys total installed generating capacity at the end of 2004 and maybe three times the potential of onshore sites. The goal is to have 20 GW of wind energy generating capacity installed by 2020, equivalent to around 1 per cent of annual electricity consumption at that time, Mr. Pengfei said.

Philippines launches national programme to use ethanol fuel

Ms. Macapagal Arroyo, President of the Philippines, launched a national bio-ethanol programme aimed at promoting the use of ethanol as a fuel additive to ease the countrys dependence on oil importation. Ms. Arroyo also witnessed the signing of contracts for the construction of the countrys first ethanol and power plant. An investment agreement was signed between the United Kingdom-based firm Bronzeoak and National Development Corp. (NDC) to ensure equity capital for the plant.

The new facility will be built by San Carlos Bioenergy Inc. (SCBI), a joint venture of Bronzeoak Philippines, three groups of sugar planters and NDC. Successful use of ethanol blends, along with energy production from sugar, would reduce the volume of the countrys oil imports, help diversify the sugar industry as well as provide extra income to sugar planters and workers. Problems of excess production, by as much as 200,000 t, which producers were saddled with in the past can now be used for ethanol production.

India explores thepotential of biodiesel

At present, India requires about 111 million tonnes of petroleum products annually. Of this, about 33 million tonnes is produced in the country as crude oil, i.e. less than 30 per cent of the requirements are met from domestic sources. Processing of crude oil yields different petroleum products and the most significant of them, in terms of consumption, is high-speed diesel (HSD) popularly described as diesel. Approximately 40 million tonnes HSD is consumed annually, which is around 36 per cent of the total consumption of all petroleum products.

Production of biodiesel from edible and non-edible oil-bearing seeds has attracted the attention of governments the world over, particularly in Europe and America. In India, R&D institutions like Indian Oil R&D Centre have been experimenting with biodiesel production from jatropha (Jatropha curcas) and other edible oil seeds. Presently, tests are being carried out on blending biodiesel with diesel to the extent of 5 per cent to establish efficacy under Indian climatic conditions. The Petroleum Conservation and Research Association (PCRA) has opened a Biofuel Centre at its headquarters in New Delhi. It is working on building awareness for jatropha cultivation as well as manufacture of biodiesel. The oil companies, Indian Oil Corporation (IOC) and Hindustan Petroleum Corporation (HPCL) are trying out various blends of the green fuel with diesel in state transport buses of Haryana, Gujarat and Mumbai.

IOC (R&D) has probed and optimized synthetic processes for preparing biodiesel from various vegetable oils, including those from jatropha, rice bran, palm, karanjia (Pongamia pinnata), sunflower, etc. The process has been scaled up to pilot plant level. The developed technology was transferred to Venus Ethoxyethers on an non-exclusive basis and on nominal technology fee and royalty sharing mechanism. IOC (R&D) has also set up a quality control laboratory at Faridabad. All quality control equipment have been installed to check the quality of biodiesel, according to ASTM/BIS specifications. In addition, IOC has entered into an MoU with Indian Railways to investigate the complete value chain of biodiesel. In line with that, IOC has taken up plantation on 70 ha of land and planted more than 100,000 jatropha saplings at the site. This project is one of its kind in the country where every aspect of jatropha biodiesel would be scrutinized. Efforts that go into bringing about this change would create enormous opportunities in supplementing the availability of hydrocarbons, and also realize socio-economic benefits such as creating fresh employment avenues, reducing green houses gases and as such being eco-friendly, etc.

Philippines to offer 18 sites for wind power development

Following the inauguration of the largest wind farm in Southeast Asia, the Philippine Department of Energy will offer 18 additional wind power sites for development, Mr. Raphael Lotilla, Energy Secretary, said. The sites at Luzon (10), the Visayas (7) and Mindanao (1) would be offered at the 2nd Wind Power Contracting Round that will be held within the year. Earlier this year, the department offered 16 wind power sites in the first Contracting Round.

SOLAR ENERGY

New line of solar modules

Innergy Power Corp. Inc., the United States, is introducing a new line of solar modules. The fibreglass reinforced panel (FRP) solar modules are designed to meet a broad range of applications where quality, durability, rugged construction and light weight are primary needs. These modules can be paired with Innergy Powers ThinLine rechargeable sealed lead batteries, thereby providing a unique renewable energy power solution for applications such as logistics tracking, asset management systems, off-grid lighting, mobile communications, mobile computing, recreational vehicles, signalling devices and surveillance cameras.

The FRP line includes solar modules with output ranging from 1.5 to 75 W.

High-efficiency solar panels

SunPower Corp., the United States, has launched a new line of high-efficiency solar-electric panels that offer customers higher power density than the companys current solar panels. Several novel performance-enhancing features are incorporated in this product line, including larger area solar cells that improve power generation within the existing panel dimensions.

The new product line includes three solar panels rated at 100 W (SPR-100), 215 W (SPR-215) and 220 W (SPR-220). With panel efficiencies of up to 18.3 per cent, these products generate nearly 50 per cent more power in a given roof area compared with conventional solar panels, and also reduce per-kilowatt installation costs. SPR-215 panel incorporates the companys all-black design that enhances the appearance of roof-mounted solar systems.

The new panel line will be available in North America and Europe by late 2005. Contact: SunPower Corp., # 430, Indio Way, Sunnyvale, CA 94085, United States of America. Tel: +1 (408) 9910 900; Fax: +1 (408) 7397 713

New solar modules from Sharp

Sharp Corp., Japan, has introduced solar energy products targeted at the rapidly growing industrial market sector. Two models based on newly developed crystalline thin-film photovoltaic (PV) modules are to be released shortly. Other products in the pipeline include nine models of polycrystalline and single crystal PV modules suitable for a wide range of applications and sites, including large-scale systems and those for installation at high altitudes, heavy snow regions and areas subject to salt air damage.

NA-8501P crystalline thin-film PV module utilizes crystalline thin-film tandem PV cells with a proprietary structure that combines the technologies of amorphous silicon and crystal thin-film silicon. The device achieves a conversion efficiency 1.5 times that of traditional amorphous silicon modules. NA-58APN1 is a translucent module with an attractive design, which permits natural lighting to shine through during daytime. ND-V0L1H PV module, which is intended for large-scale systems, achieves 210 W output utilizing 20 per cent less panels than the earlier models, allowing users to reduce installation costs. NE-80L3H, NE-80L4H, NT-87L3H and NT-87L4H PV modules for high altitudes are 30 per cent stronger than older models.

Solar absorber for flat collector

Newport Corp., the United States, has launched Oriel Class A Solar Simulator designed to help PV cell manufacturers increase production volumes and improve cell uniformity. The Class A standard was developed to enable manufacturers of PV cells comply with higher volume and cell uniformity specifications. Through ensuring measurement uniformity that allows results comparability and traceability, Class A systems decrease the process and binning variability of PV module testing when compared with Class B or non-classified sources. Each Oriel Class A Solar Simulator is factory certified to meet IEC 904-9 standards in the three required performance areas spectral comparison with the solar spectrum, spatial uniformity and temporal stability. On request, the company can also factory certify to JIS and ASTM standards.

Oriel Class A Solar Simulators are long lived, highly reliable instruments that are designed specifically for 24 7 production environments. They are offered in 2 2 to 8 8 inch output beam sizes.

Inexpensive PV

In the United States, NanoHorizons Inc. is offering a new PV design that allows dramatic improvements in cell efficiency and significant reductions in fabrication costs. Unlike conventional PV designs that utilize two different absorption and collection layers, the new design uses a single nanoscale-engineered structure to perform both absorption and collection. An array of vertically aligned collector nano-spikes made of nanofibres, nanowires, nanotubes or nanoparticle chains rise through-out a light-absorptive material layer. Integration of these nano-spike collectors into the absorption material permits power collection at 90 to the absorption process. This novel design enables photovoltaics builders to use an optimally thick absorption layer while dramatically decreasing collection distance by as much as thousand fold.

Transparent cells

XsunX Inc., the United States, has developed novel low-temperature manufacturing techniques for the production of transparent solar cells on inexpensive true thin-film plastic. The companys innovative Power Glass technology enables glass windows to produce electricity from sunlight. This technology is intended to allow PV material, in the form of photoelectric panels on thin-film plastics, to be incorporated into the glass skin of a building, thereby providing a new and innovative way to integrate additional sources of power production into the operation of buildings.

Recent expansion of the companys R&D capabilities and the addition of technical expertise in important research areas of thin films have resulted in new prototypes of Power Glass on transparent polyesters like PET and polyethylene naphthalate (PEN). This represents a major milestone as these plastics require low processing temperatures and typify some of the thinnest, lightest and least expensive substrates for solar cell manufacturing. The company anticipates that the use of PET and PEN plastics to produce large rolls of true thin-film transparent solar cells may represent a high degree of commercial viability to the multi-billion dollar glass/high-performance coatings industry.

New solar-powered sensor module

EnOcean Inc. of the United States and Germanys EnOcean GmbH have jointly launched a small, solar-powered, wireless sensor module that overcomes the challenges of power-hungry radios and battery deficiencies such as limited life,and maintenance and disposal issues. SMT100 offers a custom two-stage solar cell, where one stage offers quick start-up energy while the other charges an on-board energy reservoir. The device, designed to operate indoors, needs only 200 lux to generate energy. It incorporates a solar cell energy source, an energy reservoir, both analog and digital sensor links, a microprocessor for sensor control and a radio transmitter. This module with a 2 4 1 cm footprint, can store adequate energy to operate continuously for up to five days in complete darkness.

Each module ensures reliable wireless communication through RF protocols (multiple broadcasts, fast data rate, error detection and unique addressing). By combining solar power and radio frequency, EnOcean has completely eliminated the need for batteries in sensor applications and done away with regular system maintenance. The SMT100 platform supports a wide array of sensors (temperature, gas, humidity, location, illumination, presence, etc.) to enable mobile and maintenance-free monitoring and control of buildings, factories, logistics and automobiles. SMT100, including solar cell, energy reservoir and radio, is available in OEM quantities for less than US$25.

WIND ENERGY

Large turbines to be set offshore

A United Kingdom-based company plans to build a revolutionary offshore wind turbine designed to produce three times as much electricity as the largest models installed on land. Engineers have drawn up plans for a 9 MW offshore machine, which will be twice as wide and higher than the London Eye. Capable of providing adequate energy for around 9,000 homes, Aerogenerator is a novel design based around eight blades set into a giant V-shape spinning on a vertical axis.

Wind Power Ltd. has worked with Grimshaw, the architectural practice behind the Eden Project, to make its 400 ft tall design more aesthetically pleasing. Designers report that Aerogenerator necessitates less maintenance and should have a life span of 35-40 years, compared with the 25 years expected of horizontal axis models.

Floating wind turbines

Researchers in the United States are investigating floating wind turbine technologies that may be deployed in water depths of up to 300 m for cost-effective power generation. The coupled dynamics of a wind turbine mounted on a tethered Tension Leg Platform (TLP) has been studied by coupling the simulation tool MSC Adams with the aerodynamics and structural dynamics code FAST. Statistics for a 1.5 MW wind turbine mounted on the TLP floater are height of the rotor hub above the free surface - 84 m, 35 m blade radius, turbine rotational speed - 20 rpm, buoy diameter - 10 m, draft - 12 m, and length of the radial arms - 20 m. The studies considered two water depths 100 m and 200 m.

Comparative analysis was carried out on two alternative wind turbine floater theories a TLP known as Concept 1 and a spread-moored Spar Buoy or Concept 2. A linear dynamic analysis carried out in the frequency domain by the SWIM-MOTIONS-LINES (SML) suite of programs found Concept 1 to be relatively soft in surge and sway but extremely stiff in rotational modes. In contrast, Concept 2 was stiff in surge and sway but softer in the rotational modes.

Special axis control for wind turbines

The United States-based Moog has developed a unique pitch control valve that uses the latest digital technology for position control of wind turbines for MADE Tecnologias Renovables S.A. This intelligent servovalve is enhanced with digital communication and embedded with motion control capabilities that enables it to close the position loop within the valve.

Axis control functionality is a breakthrough development that facilitates reliability, performance as well as remote diagnostics and process control in one device, which could never be achieved with conventional valve technology. The intelligence embedded in this device also helps eliminate the cost and complexity of an external controller (PLC).

The motion control system Moog developed together with MADE is part of Moogs new hydraulic valve platform, the Axis Control Valve with CAN-bus interface (D636 and D637 series). The product is based on a proven servovalve design. For the pitch control servovalve, Moog has also developed flexible configuration software for axis control. Moog is even supplying prototypes of its Radial Piston Pump (RKP), which will be in a dual pump arrangement on the same shaft for cost savings. Other features of the Moog solution include a fail-safe system in the valve to synchronize the movement to home position in the case of a PLC fault, thereby ensuring maximum safety protection.

New wind turbines

In the United States, OGE Energy Corporation operates 34 turbines manufactured by General Electric Co. The computer-controlled units generate power in winds ranging from 10.78 to 88.5 km/h, with peak performance at around 42 km/h. For safety, the turbines automatically shut down if wind speeds exceed 88.5 km/h. A shaft extending from the three rotating blades drives a generator, converting mechanical motion into electricity, which flows through high-capacity cables to a nearby substation, where the voltage is stepped up and delivered to the companys power grid.

Each turbine blade is 113 ft long and rotates 18-22 times per minute. The nacelle, a housing that encases the generator and connects with the blades, automatically rotates to face the wind, no matter which way it is blowing. All of this is mounted atop a tower, 212 ft above the ground. The generator produces 1,500 kW from a blade-sweep area of about 15,000 ft2.

BIOMASS ENERGY

IIT develops biodiesel engine

A car engine that runs on biodiesel has been developed in India by the Indian Institute of Technology (IIT), Delhi. Dr. M.K. Gajendra Babu, Head of the Department, Centre for Energy Studies, IIT-Delhi, drove a passenger car fitted with the biodiesel engine for display at ASSOCHAM House where he addressed a conference on Commercialization of Energy Efficient Technologies. According to Dr. Babu, programmes are afoot to introduce passenger cars based on the indigenous engine by the time biodiesel fuel is made available for mass consumption. At present, on an experimental basis, 10 per cent of the biodiesel fuel is mixed with diesel to run the automobile.

In another development, Ms. Leena Mehendale, Executive Director of Petroleum Conservation Research Association (PCRA), stated that PCRA and the Indian Institute of Petroleum have jointly developed energy efficient burners and pump sets for agricultural purposes. These burners and pump sets can replace over seven million obsolete pump sets in which the energy efficiency is less than 30 per cent.

New process yields fuel from plants

In the United States, scientists at the University of Wisconsin-Madisons College of Engineering have discovered a new process to obtain fuel from carbohydrates found in plants. Prof. James Dumesic et al. developed the four-phase catalytic reactor in which corn and other biomass-derived carbohydrates can be converted into sulphur-free liquid alkanes to obtain an ideal additive for diesel fuel. It is a very efficient process, says Mr. George Huber, a co-researcher. The fuel produced contains 90 per cent of the energy present in the carbohydrate and hydrogen feed. If you consider a carbohydrate source like corn, our method has the potential to generate twice the energy as is created in using corn to make ethanol.

Around 67 per cent of the energy required to make ethanol is used in fermenting and distilling corn. As a result, ethanol production creates 1.1 units of energy for every unit of energy utilized. The new process spontaneously isolates the desired alkanes from water. No additional heating or distillation is necessary, resulting in the creation of 2.2 units of energy for every unit of energy consumed in energy production.

Ethanol research breakthrough: Wood feedstock

As opposed to an annual crop like corn, wood has the potential to offer a year-round source of ethanol, and still supply a feedstock for biomass thermal energy or co-fired plants. In the United States, researchers at SUNY College of Environmental Science and Forestry (ESF) report to have invented a new method for removing energy-rich sugars from wood, a procedure that could help develop agricultural feedstocks for ethanol production. Designed by Dr. Thomas E. Amidon, the process would facilitate the economically significant pulp and paper industry develop more efficient and sustainable biorefineries.

Cellulose, a polysaccharide (sugar), is one of the basic components of wood and also the most widely used component of woody plants. It becomes pulp for use in making paper. The second largest component of hardwood trees is xylan, another polysaccharide that is primarily dissolved in the pulping process. According to Dr. Amidon, the real value in xylan has never been exploited! Once fermented, this sugar yields ethanol, which can be used in cars instead of, or in combination with, traditional petroleum. Though energy factor is the focus of attention now, there is a second advantage to the process. In addition to extracting sugar from wood, scientists could isolate the woods acetic acid. A major use of acetic acid is in the manufacture of polyvinyl acetate, a plastic utilized in many aspects of home construction and several other consumer products. The commercial value of acetic acid is nearly three times that of ethanol US$0.45 per pound as opposed to US$0.18 per pound. One of the advantages of this process is that no harsh chemicals are required.

Pilot plant extracts energy from manure

Canadas Alberta Research Council (ARC) and Highmark Renewables have jointly set up a pilot plant that demonstrates a new technology to transform manure into energy, bio-based fertilizers and reusable water, while decreasing greenhouse gas emissions and other environmental impacts related with land application of manure. The Integrated Manure Utilization System (IMUS) combines anaerobic digestion, biogas usage, liquid/solid separation, nutrient recovery and enrichment processes. Methane gas produced through anaerobic digestion is used for power and heat generation. Innovative and highly efficient processes recover and concentrate nutrients from the digested liquid to yield pathogen-free bio-based fertilizers.

FUEL CELLS

Hydrogen fuel cell

The United States-based Progress Energy Florida and Florida Department of Environmental Protection (DEP) and Canadas Hydrogenics Corp., a manufacturer of fuel cell technology, have unveiled a sustainable hydrogen generator and fuel cell at the Homosassa Springs Wildlife State Park. Progress Energy and DEP jointly funded the project while Hydrogenics provided the hydrogen generation system. The integrated fuel cell and 5 kW PV solar system are supplementing a portion of the electricity used at the parks Wildlife Encounter Pavilion, which provides educational programming to visitors.

Propane-driven fuel cell

In the United States, researchers from Southern California University, the California Institute of Technology and North-western University have developed a propane-driven fuel cell that is the same size as a lithium battery, but lasts 10 times longer. Propane (the same fuel used in gas barbecues) and other large hydrocarbons are desirable because their larger molecules pack more energy and can be easily stored as liquids rather than as pressurized gases. A small cartridge of liquid propane under moderate pressure could feed a fuel cell for days.

The dime-sized prototype fuel cells were designed to heat themselves up to 500-600C, needed to convert propane into electricity. To build a self-heating feature into the design, researchers coated one electrode of the fuel cell with a catalyst (ruthenium and cerium dioxide mixture) that promotes the breakdown of propane by oxygen. This reaction releases heat and produces carbon monoxide and hydrogen, which then undergo electrochemical reactions in the fuel cell. The result is electricity, with carbon dioxide and water as the waste products.

In an experiment, catalytic oxidation of propane in the fuel cell produced enough heat to sustain the fuel cell for 200 h while in another test, a pair of the fuel cells, wrapped in thermal insulation, produced sufficient power to operate a 1.5 V MP3 player. However, a glitch with the prototype is that to initiate the catalytic reaction, the fuel cell has to be first heated to 300C for about a minute inside a furnace. Once the fuel cell reaches this temperature, it can generate its own heat.

New discovery may lead to miniature energy sources

A new process for generating heat required by fuel cells to function could allow lighter, more powerful batteries for mobile electronics. The technology was developed in the United States by researchers from the University of Southern California, the North-western University and Caltech. It eliminates the need for separate heat sources to catalyze the hydrogen-oxygen reaction that generates electricity from fuel cells, enabling their miniaturization. Study author Mr. Paul Ronney forecasts that laptop computers would be the first electronics to employ the new fuel cells. This technology also has important military applications, too. The energy sources may be available commercially in about 5-10 years.

Study on platinum-gold electrocatalysts

Scientists at New York University, the United States, have investigated the potential of employing gold and gold-platinum nanoparticle electrocatalysts for fuel cell reaction at the cathode. Electrocatalytic oxygen reduction reaction (ORR) activity was characterized by voltametric and rotating disk electrode assays. Additionally, current catalysts were compared under the same measurement conditions.

Catalysts were prepared by a two-stage protocol and activated thermally using calcination temperatures. Results have shown that gold and gold-platinum nanoparticle catalysts are potentially viable candidates for fuel cell catalysts under a number of conditions. However, the electrocatalytic properties depend to a considerable extent on the gold-platinum composition. Experts claim that this study provides important information on the electrocatalytic activity of catalysts and will help in the design of highly active fuel cell catalysts.

Fuel cell technology breakthrough

The United Kingdom-based CMR Fuel Cells reports to have achieved a breakthrough with a new design of fuel cell that is a tenth the size of existing models and small enough to replace conventional batteries in laptop computers. This development may help unlock the vast potential of fuel cells as a commercially viable source of green energy. Mr. John Halfpenny, CMRs Chief Executive, stated that their new technology is comparable to the transition from transistors to integrated circuits.

The new design operates four times longer than conventional batteries in a laptop or other devices like power tools. Its also instantly rechargeable, said Mr. Michael Priestnall, Chief Technology Officer at CMR. Mr. Priestnall and Chief Engineer Mr. Michael Evans came up with the design while working at Generics Group. Mr. Evans said the design, which would operate initially using methanol, was based on a new type of fuel stack that mixed air and fuel. Up to now, fuel stacks have typically relied on total separation of the two.

Latest developments in fuel cell technology

The Fraunhofer Institute for Ceramic Technologies and Sintered Materials (IKTS), Germany, is offering durable SOFC stacks, that can be operated with fossil fuels or biogas, intended for application in distributed power supplies. The SOFC stacks yield 1 kWe and have an estimated lifetime of 40,000 h. Overall efficiency value of the SOFC, around 80 per cent, is a particular advantage. In distributed applications like CHP systems, stack units in the power range 1-5 kWe are essential. The remaining system components are take care of purification and supply of the fuel gas, distribution and use of the heat, and voltage conversion to 220 Vac.

Also, an extremely thin Ag/Zn micro-battery for integration in sensor cards is available. The 0.5 mm thick micro-battery is intended for mobile, highly integrated and low-cost applications, preferably in credit card format. The primary battery comprises a silver oxide cathode and a zinc anode, which are deposited with thick-film technology on to the collectors. With a capacity of 15 mAh and an output voltage of 1.5 V, the micro-battery is meant for integration into miniaturized electronic products, together with sensors, electronics and data interfaces.

Fraunhofer Institute for Solar Energy Systems (ISE) has introduced a weather-resistant, near-industrial prototype of a miniature fuel cell that can operate in the temperature range of -20-40C. By ingeniously guiding hot and cold air currents via a novel casing, system heating or cooling is supported as required. Innovative microprocessor controls enable the system to start reliably at -20C and still operate safely at temperatures exceeding 40C. The target markets for this fuel cell are applications in off-grid measurement and controls technology.

Direct methanol technology unveiled

DuPont Fuel Cells announced its latest know-how for a new generation of Membrane Electrode Assemblies (MEA) components enabling direct methanol fuel cells with improved overall power performance and long run-times. Gen IV MEA technology of DuPont requires significantly less catalyst loading, compared with the previous generation, while still delivering about 20 per cent increase in power density and over two times improvement in durability and reliability, leading to cost-effective fuel cell systems.

This new technology is facilitating development of direct methanol fuel cells by original equipment manufacturers targetting portable power in consumer electronics, including laptops and mobile phones, as well as in larger units for recreational, military and industrial applications.

Direct fuel cell power plant

The United States-based FuelCell Energy Inc. has integrated design changes to a 250 kW direct fuel cell (DFC) power plant, resulting in 25 per cent cost reduction. DFC power plants generate electricity without combustion. Their highly efficient electrochemical reactor units are thousands of times cleaner than facilities burning fossil fuels and significantly quieter. These traits make fuel cell power appropriate for producing base load electricity where customers have to face cost, reliability, security or environmental issues with their existing electric power sources in settings which include municipal/industrial wastewater treatment facilities,data/telecommunications centres, hotels, universities, manufacturing plants, hospitals and medical institutions, prisons, etc.

Apart from lower capital costs, the DFC300MA power plant is expected to reduce maintenance costs. This is achieved through a modular three-piece design, with separate skids for the mechanical balance of plant, electronic balance of plant and the DFC module. Additional improvements include modifying certain subsystems, so that materials and parts may be sourced from multiple vendors, and automating the fuel cell conditioning process, resulting in higher product quality. Design enhancements to the sub-megawatt DFC power plant will be extended to the megawatt plant design. After final verification, the DFC300MA power plant will begin shipping in the last quarter of 2005.

HYDROGEN ENERGY

First anniversary of hydrogen generator

HyRadix Inc., the United States, announced today that its 100 Nm3/h Adeo hydrogen fuel generator completed a full year of operation at SunLine Transit Agency. The fuel generator makes use of proprietary technology developed by HyRadix to convert natural gas/propane into high-purity, ultra-low CO hydrogen for refuelling hydrogen automobiles. During the first year of operation, the HyRadix Adeo unit logged over 4,400 h of operation.

Zero-emission power source

ZAP, the United States, announced the successful demonstration of a technology to power zero-emission hydrogen fuel cell cars. The company is pioneering the next generation of advanced transportation and energy technologies, along with technology partner Apollo Energy Systems. Apollos Alkaline Fuel Cells, derived from designs used in most major space exploration programmes, are hydrogen fuel cells that derive their energy from ammonia. The patented Ammonia Cracker procedure from Apollo breaks ammonia down into hydrogen to power the fuel cell. This technology ensures a range of cost savings and other advantages over competing hydrogen cell solutions.

According to Mr. Robert Aronsson, President of Apollo, Our fuel cell technology can easily jump-start the hydrogen economy. The simplest and least expensive way to move hydrogen is as ammonia (NH3), 75 per cent of which is hydrogen. NH3 could be added inexpensively as a component of todays fossil fuel stations, without costly hydrogen extractors, allowing the fuelling of fuel cell cars today, years ahead of other hydrogen solutions.

ZAP has an exclusive licensing and distribution agreement with Apollo Energy Systems for its proprietary Alkaline Fuel Cell, Ammonia Cracker and Lead-Cobalt battery know-how as a contract towards the development of ZAP CARS powered by hydrogen fuel cells. ZAP will work with Apollo to create a prototype fuel cell vehicle using the DOT-approved Smart Car. Powered by a 60 kW Apollo Fuel Cell and equipped with a 39.5 l NH3 fuel tank, the Smart Car will have a cruising range of up to 321.8 km per refuelling, that too with zero emissions.

According to ZAP CEO Mr. Steve Schneider, This technology has the potential to enable ZAP to offer a true zero-emission vehicle that can satisfy the transportation needs of drivers in the country. Hydrogen required for the fuel cells will come from liquid NH3 that would be stored in large tanks at gas stations. The electric vehicles would fill up liquid NH3, which then feeds into Apollos patented Ammonia Cracker onboard the automobile, similar to catalytic converters in modern automobiles. The Ammonia Cracker will convert NH3 into hydrogen for the fuel cells.

Hydrogen production demonstration unit unveiled

Canadas Alternate Energy Corp. (AEC) recently demonstrated the first alpha-stage model of its on-demand hydrogen production process. H2 1500-A1 was established on-site at two multinational firms based in the United States. AEC is on schedule with an accelerated product development timetable to take advantage of several openings with targeted organizations. It will be showcasing proprietary know-how to a long list of prospective commercial customers, potential licencees, select government and institutional contacts, etc. These groups have been pre-qualified as having an established need for clean non-conventional energy.

Water used to produce hydrogen

Scientists at the University of Pittsburgh, the United States, have recently announced what could be a step towards using water for fuel. Prof. Hrvoje Petek and the chair of the Dept. of Chemistry, Mr. Kenneth Jordan, produced wet electrons by exciting the surface of a metal oxide with a laser. Excitation of the metal oxide promoted transportation of electrons from titanium ions in the interior of the metal oxide to a layer of water outside. Molecules of water then stabilized the electrons hence the name wet electrons.

Wet electrons provide the lowest energy pathway to move electrons between solid and liquid states, and could one day help produce a cleaner fuel source. Since titanium dioxide the metal oxide used in this experiment is a photocatalyst, it can break water molecules into oxygen and hydrogen whenever its electrons are excited by exposure to ultraviolet light.

However, in this case, the crystalline structure of titanium dioxide was a type that is not very active in photocatalysis. Prof. Petek said that it might be possible to split water into hydrogen and oxygen at an efficient rate if the process was carried out with a more photochemically active species of titanium dioxide.

Nanotubes promise fuel from water

Sandia National Laboratories, the United States, demonstrated that hollow organic nanotubes, conjoined to an inorganic catalyst, can capture sunlight to convert water into pure hydrogen and oxygen. Prototypes from which a new kind of solar cell capable of yielding fuel from water are expected to be available by 2006.

Organic nanotubes are employed throughout nature for transporting electrons and to convert light into energy. Researchers believe they can harness the same mechanism to power automobiles using water. The team exhibited that porphyrin nanotubes can be prepared in an aqueous solution by virtue of ionic self-assembly of a pair of oppositely charged porphyrins. Researchers added metal ions to the solution to coat the outside of a nanotube with catalytic platinum as well as grow a gold wire complete with a contact ball for connecting the hydrogen harvesting part of the nanodevice to the part that harvests oxygen down the centre of the two connected nanotubes. That functions as the connector between the two pieces of the nanodevice.

The tube is itself photocatalytic and generates hydrogen. The next step for the team is to create a device that marries the hydrogen producing and oxygen producing parts at the nanoscale.

New way to produce hydrogen

Signa, the United States, reports to have devised a new and fairly efficient process to obtain hydrogen. The key to this low-cost process is sodium, an alkali metal that bursts into sparks when dipped in water. The sodium/water reaction produces hydrogen and other by-products.

Signas technique involves mixing sodium with silica gel or crystalline silicon for generating energy that essentially strips electrons from the sodium molecules in advance and stores them. When water is added, the reaction will not produce sparks or intense heat. Harvested hydrogen molecules in turn undergo a second reaction; electrons are stripped from the molecules and get channelled into electricity. More than 9 per cent of 1 kg of the powder is transformed into hydrogen while a small amount of energy is lost as heat.

The powder for fuel cells comprises sodium amalgamated with a silica gel. Though this mixture yields less overall hydrogen than the sodium/crystal silicon blend, the potential for impurities is reduced. The firm is working with a fuel cell manufacturer to develop prototypes.

Graphite: Magic bullet for hydrogen storage problems?

Physicists in Canada and Germany have proposed a new technique to store hydrogen. The method, which involves storing the gas between layers of graphite just nanometres thick, could be the solution that researchers have long been looking for as a practical hydrogen-storage device for fuel cells.

Mr. John Tse et al. at the Steacie Institute for Molecular Sciences in Canada and the Technical University of Dresden, Germany, re-analysed graphite with the aid of mathematical models. They found that previous studies did not consider interactions between hydrogen and carbon on the quantum scale, which led to misleading decisions for the absorption capacity of this material. Including such interactions involves solving the Schrodinger equation for the motion of hydrogen atoms on the complicated potential energy surface of graphite.

According to the latest calculations, thin layers of graphite or graphene, two-dimensional sheets of carbon atoms, spaced between 6 and 7 apart can store hydrogen at room temperature and minimal pressures of around 10 MPa. Moreover, the amount of hydrogen stored is close to the practical goal of 62 kg/m3 as stipulated by the United States Department of Energy. Another key benefit is that the hydrogen gas can be released by moderate warming. The Canadian-German team reports that it can create tuneable graphite nanostructures with different storage properties by interposing spacer molecules between graphite layers. These spacers would facilitate the additional benefit of keeping out contaminants such as nitrogen and carbon monoxide, which can lower hydrogen storage capacity. Mr. Tse states that now the technological hurdle is to synthesize graphenes with appropriate interplanar spacing for maximum hydrogen adsorption.

WASTE-TO-ENERGY

Waste-to-energy gasification

Global Environment Energy Corp. (GEEC) is offering an eco-friendly gasification process for extracting energy from wastes. Biosphere can produce power and heat from unseparated MSW, hazardous refuse and a range of other waste streams, including contaminated topsoil. A significant feature of this process is that no toxic emissions are produced. GEECs technology can produce a minimum of 5 MWh of electricity from 5-7 t of waste, with potable water, fertilizer, cement, compost and reclaimed metals as the by-products. The company plans to set up over a thousand renewable energy plants, based on Biosphere technology, in China.

Waste Management World, March-April 2005

Waste-to-power fuel cells investigated

Intestinal bacteria feasting on wastewater could power homes one day if experimental technology designed by a group of Washington University engineers works out. Mr. Zhen, Mr. Shelley D. Minteer and Mr. Largus T. Angenent have devised electricity generators, or fuel cells, fired by bacteria and wastewater. For now, the fuel cells are almost a million times less powerful than hydrogen fuel cells used to power vehicles. The team hopes to scale up the coffee-thermos-sized reactor into a plant that could process millions of litres of brewery or other food production wastewater into electricity for up to 900 homes.

The new technology is based on the discovery that some of the bacteria that digest food in the human gut can also serve as mini-generators. Researchers have built a tiny wastewater treatment plant from large test tubes filled with murky water. Bacteria and methane-producing Archaea, a class of single-celled organisms that resemble bacteria, in the solution settle down on the carbon electrodes resembling bricks of steel wool. As the microbes break down organic material they give up electrons, which is harvested. The bacteria feed on a solution of sugar water, but large-scale reactors would run on wastewater let out by food processing facilities. Even sewage could be used, but it has a lower concentration of organic matter and probably will produce only enough electricity to make a sewage treatment plant self-sufficient.

Wastewater is sent into a stacked reactor at the bottom and electricity is obtained at the top. Such reactors could save space and also eliminate the need to stir the waste, thereby lowering the amount of electricity needed to fuel the reactor. The lab-scale reactor generates about 170 mW/m2 of electricity, which is not even sufficient to power a light bulb. However, in large-scale (over 9 million litres) plants, such wastewater fuel cells could generate adequate power for a small town.

Co-production of ethanol and energy

In the United States, a gasification/biocatalytic process developed for BRI Energy allows for concurrent production of electricity and ethanol (and/or hydrogen) from any carbon-based material such as municipal solid waste, biosolids and animal wastes, biomass waste, used tyres and plastics, and also hydrocarbons (coal, natural gas, refinery tars and waste oils). Developed by a team headed by Dr. James L. Gaddy, the BRI process utilizes a culture of acetogenic bacteria (Clostridium ljungdahlii) that ingests synthesis gas (gasified wastes) and releases ethanol at a yield of about 341 l/t of dry biomass. From used tyres or hydrocarbons, approximately 682 l/t of ethanol is obtained. The process involves three main steps:

Thermal gasification: Approximately 1,205C temperature in a reducing, oxygen-starved environment cracks organic materials and reforms them into carbon monoxide, carbon dioxide and hydrogen gases. Before exposure to bacteria in a fermentation tank in the next stage, the synthesis gas is cooled to 36C, a process in which a large amount of waste heat is released that can be utilized to create high temperature steam to drive electric turbines;

The utilities used in operating a BRI plant, with the exception of water, can be supplied internally from the plants waste heat. The whole process, from the time that waste is fed into the gasifier to the creation of ethanol, takes less than 7 min. The plant design is governed by the maximum size of current gasifiers. BRIs plants are modular and their capacities can be expanded. A mid-sized BRI renewable energy plant can process 1,000,000 t/y of MSW, waste tyres and/or biosolids, yielding 364 million litres of ethanol and 50 MW of power, 35 MW of which is excess to the operation of the plant. Such a plant will need ten modules and approximately 30 acres of land.

Fuel gas production from waste plastics

In Japan, the Research Institute for Environmental Management Technology of the National Institute of Advanced Industrial Science and Technology has developed direct gasification technology to obtain fuel gas from waste plastics. The Polymer Decomposition Laboratory Co., Ltd. (PDL) also participated in this project. Although several oil production processes were devised over the past three decades, technical and economic obstacles still remain for a process that recycles waste plastics. The recent breakthrough offers an innovative method to promote a more economical way of feedstock recycling.

Based on the process design by PDL, an experimental module with a horizontally placed moving-bed reactor for plastics decomposition was assembled and operated to ascertain optimum conditions for the effective formation of gaseous hydrocarbons. A mixture of gaseous hydrocarbons such as methane and isobutane were obtained from polyethylene and polypropylene with 70-94 wt per cent. Effective gasification was achieved through steady heat transfer using a screw conveyor and sand mixing with plastics, two crucial features of the gasification module. Mixed gas thus obtained had higher economical value than heavy oil substitutes, a major product of the conventional process of feedstock recycling. Researchers plan to build a demonstration plant and other reactors for precise control of the gas compositions.

High-temperature gasification

Thermoselect SA, Switzerland, has developed a new high-temperature gasification technology that accepts a wide range of wastes to produce purified syngas as well as granulate metals and minerals that can be used in industry and construction. Thermoselects process has the potential to provide an alternative to the conventional practice of landfilling wastes. This process does not lead to the creation of dioxins, furans and other organic compounds.

The process recovers synthesis gas, usable vitreous mineral substances and iron-rich materials from MSW and commercial/industrial wastes. The uninterrupted procedure concurrently gasifies organic wastes while melting down inert materials. Organic materials are converted to synthesis gas with a composition that reflects the thermodynamic equilibrium of the temperature at the top of the reactor, about 1,200C. The high-temperature, oxygen-free environment and a residence time of over 2 s in the upper part of the reactor ensures that the prime constituents of the exiting syngas only occur as the smallest molecular species of hydrogen (H2), carbon monoxide and dioxide (CO, CO2) and water.

At an outlet temperature of 1,200C, synthesis gas obtained from the organic fraction of MSW typically comprises (by volume) 25-42 per cent H2, 25-42 per cent CO, 10-35 per cent CO2, 2-5 per cent nitrogen, up to 1 per cent methane, H2S as trace amount and other impurities. Subsequent purification of synthesis gas and process water yields by-products in the form of salt, zinc concentrate and sulphur. Moreover, there is no deposition of ash, slag, chars or filter dusts.

Methane from organic wastes

In the Republic of Korea, research undertaken by Kobiotech Co. Ltd. has resulted in a technology capable of producing clean biogas through high-speed methane fermentation of organic wastes. This project was funded by The Core Environmental Technology Development Project for Next Generation, of the Ministry of Environment.

The new process is highly effective, taking only 12 days for the whole procedure. About 90.6 per cent of COD is removed and 245 l of gas recovered from 1 kg of COD. Economic viability is achieved using a pH controlling liquid for operating the semi-anaerobic hydrolysis/acid fermentation tank. The waste liquid accumulated after fermentation of the organic wastes can be used as fertilizer to raise high-quality crops. Potential uses of the process are:

Processing highly concentrated organic wastes and wastewater;

A small system can be installed to treat food wastes and even utilize the energy thus generated; and

In large-scale applications, the system can treat food wastes in a district and use the methane as an energy source.

A 2.5 t and 10 t 3-stage methane fermentation systems installed at Chosun University could treat 100 kg/d and 400 kg/d, respectively, of food wastes. Methane produced on the campus is used to meet heat requirements.

PUBLICATIONS

Electricity Reforms and Green Power Development

This book focuses on the need for an appropriate tariff regime and policy framework for boosting renewable energy development in India. Electricity Act 2003 was aimed to drastically reform the power sector. Inspired by the new scenario, two State Electricity Regulatory Commissions set out to formulate an approach to address issues relating to grid interconnection and tariff. Much of this book is devoted to critically analyse the larger issues arising from the pioneering orders of these Regulatory Commissions.

The New Energy Economy

This book is a compilation of essays from 19 experts drawn from senior-most levels of the academia, non-government agencies, industry and the government. Scientific estimates predict that by 2050 about 40-50 per cent of grid power would come from renewable sources. The book surveys this epochal transformation globally, with special focus on India.

Geothermal Plants: Principles, Applications and Case Studies

This single-source reference book provides information on all aspects of the utilization of geothermal energy for power generation. Grounded in fundamental scientific and engineering principles, its practical emphasis is enhanced by the use of actual case studies from historic and present-day plants.

Solar Cells: Materials,Manufacture and Operation

Going beyond materials, design and function, this book covers the testing, monitoring and calibration of solar cells. It thus provides a state-of-the art account of this important field of research and industry.

WAVE/TIDAL ENERGY

Ocean tidal stream technology

Lunar Energy Limited, the United Kingdom, has developed an Ocean Tidal Stream technology with tech- nical collaboration from Rotech Engineering Ltd., which has patented the developed technology under the name Rotech Tidal Turbine (RTT). Lunar has an exclusive worldwide licence to exploit this tidal energy generation technology. It currently offers RTT 1000, RTT 1500 and RTT 2000, which produce 1 MW, 1.5 MW and 2 MW, respectively, at 6 knots tidal flow.

Lunar RTT 1500 has an inlet diameter of 21 m and an overall length of 27 m. The five-bladed turbine has 16 m diameter. The minimum depth required is 35 m. The unit weighs 1,200 tonnes. This predictable energy resource permits fully predictable generation of electricity. Because each Lunar RTT unit is located on the sea-bed without any above-water feature, a complete farm of these units is invisible at all times. The units weight ensures stability on site without piling, and unit location and maintenance do not require diver or ROV intervention. Analyses show that the unit will be competitive with other conventional forms of electricity generation and that the mature technology will be comparable with the cost of electricity from gas/ coal. The Lunar RTT uses a symmetrical turbine in a bi-directional Venturi duct, which caters for flow reversals that deviate from 180, doing away with the need for yawing or blade pitching mechanisms. Use of a duct augments the power available at the propeller, and power increases as tidal flow moves away from the normal axis; power is not lost inside some 40 sector from the device axis. Gearing is hydraulic and all hydraulic motor and electrical generator components are placed in a hermetically sealed unit. A removable module permits the on-shore maintenance of all key components.

Tidal power pilot plant

Statkraft, Norway, is currently planning a pilot tidal power plant in the Kvalsundet Strait outside Troms. The plant is based on the idea of Mr. Svein Henriksen, an entrepreneur from Harstad. Statkraft and Mr. Henriksen jointly developed it to the pilot level. The plant will initially run on one turbine. The annual volume of energy produced by the pilot plant in the Kvalsundet Strait is expected to be 3.6 GWh, while later plants may produce almost 5 GWh. If the tests are successful, tidal power stations cmnprising several production units may be built.

The project is environment-friendly, as turbines and generators lie under the surface of the sea and will therefore not disfigure the environment. Since the tidal power stations float in the water, they do not have any major, permanent effect on the seabed either. The tidal power potential for the whole of Norway is still un-certain, though an estimate puts it at 2 TWh in north of Norway alone. At the consumption of 25 000 kWh, this is equal to the annual electricity consumption of 80 000 households.

Turbine in pipe

Turbines using existing designs can be placed inside large-bore underwater pipes to produce a reliable, clean and cost-effective source of tidal power, according to Mr. Don Cutler, founder of Tekflo, Weymouth, the United Kingdom. Mr. Cutler has now set up a company, SusGen, to develop his system in collaboration with Southampton University. A working model generating around 100 kW is to be soon tested offshore.

In the Channel, tides flow in relatively straight lines, varying from five knots to zero before the process reverses as the sea flows back. In the new design, a simple framework is attached to a reinforced-concrete base consisting of an open-ended hollow box, which is fixed to the seabed by anchors or screws. The turbine and generator are positioned in the mid-section of the box, and are fitted as a module so they can easily be removed for maintenance. Each end of the box is slightly flared to act as a funnel for the water, gathering it into a narrower section that forms the entrance to the turbine. This also extends the useful energy capture when the tides direction changes.

The design uses multi-bladed turbines driving electric generators, all of which are positioned under the sea to minimize their environmental impact. Simple six-blade turbines have achieved an efficiency of 50 per cent in tests, but SusGen is working to develop a more efficient system, featuring a twisted design where the angle of attack changes along the blade length.

New tidal turbine under test

A C$4-million joint project among Pearson College, EnCana Corporation of Canada and Clean Current Power Systems of Vancouver will harness the turbulent tides tumbling by Race Rocks ecological reserve near Metchosin and test how well a new tidal turbine generator stands up to the harsh West Coast environment. Clean Current built the prototype of a tidal turbine generator, while EnCana is investing C$3 million in the project.

The prototype being tested is 3.5 m in diameter and can produce enough electricity for 10 houses. Testing will take place in about 15 m of water. Underwater cameras will monitor the turbine. The tidal turbine generator, which functions like an underwater windmill, will be anchored to the seabed and cables will carry away the electricity it generates. The prototype has been tested in fresh water but not in saltwater. Clean Current will know in about 18 months how the model and its one moving part the rotor stands up to corrosion in a harsh marine environment.

Helical turbine gets a test run

Dr. Alexander Gorlov, a professor of mechanical engineering at the Northeastern University in Boston, the United States, is having his deceptively simple-looking prototype a barrel-shaped 36 40 inch turbine tested to assess its efficiency in harnessing the power of currents and tides. Tests are currently being conducted at a tidal pool in Maine, the United States, and in a remote area of the Amazon River in Brazil.

Dr. Gorlovs helical turbine is based on the Darrieus turbine, developed for windmills in the 1930s, which did not prove practical. When Dr. Gorlov tested it in flowing water, however, he found it worked better than any other turbine, although it still had vibration problems. After laboratory testing, he found that twisting the blades into a helix would solve the problem. In flowing water, the turbine captures 35 per cent of the waters energy, compared with 23 per cent for a straight Darrieus turbine and 20 per cent for a conventional turbine. In full production, the cost of an installed open-river hydropower system of the new turbines would be US$400-US$600 per kW, before operating costs of fossil-fuel plants are taken into account.

Novel tidal power technology

Woodshed Technologies, Australia, has been granted a United Kingdom patent for a new marine energy technology that relies on the natural rise and fall of bodies of seawater. Tidal Delay tidal power technology uses an existing natural land formation, such as a peninsula or isthmus, that creates a natural tidal barrier separating moving, rising and falling bodies of seawater. As the seawater on each side of the natural barrier rises and then falls, the turbine captures the energy resulting from the difference in water levels across the barrier, using proven hydro-electric technology in a novel configuration.

Woodshed Technologies, together with fellow Australian companies Lloyd Energy Systems and SMEC Developments, intends to develop and implement the combined Tidal Delay/Lloyd Energy Storage System projects in Britain, supporting local engineering firms in the design and construction phases of the project.

A leap in tidal technology

Hi-Spec Research & Developments Ltd., Cornwall, the United Kingdom, has developed a breakthrough in tidal technology, with a unique system that uses the tidal stream in conjunction with the natural rise and fall of the tide to create electricity. The offshore Ocean Hydro Electricity Generator (OHEG) power plant allows electricity to be generated around the clock. Based on the use of tidal and chamber turbines, combined with energy accumulators, energy is created through the natural tidal stream and the rise and fall of the tide a far more reliable energy source than wind or solar energy.

The offshore OHEG structure would consist of three rows of chambers and two outer walls, creating four channels, with the tidal stream then being diverted through these channels. Within the chambers would be groups of energy accumulators. The accumulators create power from the rise and fall of the tide. Placed between the rows of chambers and the outer walls are banks of tidal turbines, with four banks per channel. The OHEG plant holds back over 6 million tonnes of water every six and a half hours and in doing so, creates power through the chamber turbines.